As children with learning disabilities (LD) are increasingly served in general education classrooms, where response to intervention models (RTI) have become pervasive, better understanding classroom learning environments that support or do not support children with LD has the potential to improve their outcomes and reduce referrals to special education. Building on two large and unique data bases, the proposed project has three specific and inter-related aims. First, we will use a large data set that includes over 4000 children in first through fifth grade to examine instruction, teacher, and peer effects. These children participated in the NICHD funded studies on Individualizing Student Instruction in Reading (ISI, Connor, Morrison, Fishman, Schatschneider, & Undenwood, 2007) and so there are videotaped classroom observations (three per classroom ~ fall, winter, & spring) and an extensive battery of assessments including reading comprehension, decoding, phonological awareness, oral language, writing, executive functions, mathematics, and motivation. In addition, there are longitudinal data for approximately 425 children from 1st through 3rd grade and a smaller sample who were followed through 5th grade. Second, we will draw on the extensive Florida Progress Monitoring Reporting Network (PMRN) data base to follow these 4000 children through their transition to middle and high school. Third, we will conduct two experimental studies, recruiting the ISI students who will be in middle school and high school at the time ofthe experiments to better understand the mechanisms underlying reading comprehension and LD that may be related reciprocally to the classroom environment. These include enacted representation, motivation, stress, and anxiety. Broadly implemented, the results ofthe proposed studies have the potential to improve general education classrooms for children with LD and their classmates, to explicate the transition to middle and high school for children with LD and the aspects of elementary schooling that ease or interfer with these transitions, and to improve reading comprehension instruction by identifying potential mechanisms for intervention.